1. Field of the Invention
This invention relates to oral devices, appliances, mouthguards and mouth props used to prevent oral injuries of the soft tissues, i.e., lips, cheeks, tongue, and of the teeth in comatose, decerebrate and generally anesthetized patients as well as dentally anesthetized patients.
2. Description of the Related Art
Uncontrolled, uncoordinated biting, chewing, grinding and clenching movements of the mandible may cause damage to oral soft tissues, such as the tongue, cheek, mucosa, and lips, if these tissues become entrapped or impinged between the upper and lower teeth. Uncontrolled, uncoordinated biting, chewing, grinding and clenching movements of the jaws can also cause teeth and dental restorations to fracture and break. These consequences of oral injuries can precipitate the introduction of blood, debris and other material in the oral cavity and present a risk to the respiratory system of the injured patient.
Persons who are comatose, heavily anesthetized, or decerebrate can unconsciously display powerful oral movements which are extremely difficult to control and often cause traumatic lacerations and mutilation of the tongue, lips and cheeks. Persons whose mandibular nerve, lingual nerve and/or mental nerve is locally anesthetized for dental procedures, i.e., dental restorations and extractions, have a period of altered sensations to pain and pressure in their tongues, cheeks, and lower lips. Children and the developmentally disabled frequently chew and bite these anesthetized oral soft tissues causing lacerations and mutilation of tissues which may lead to permanent disfigurement.
Several oral devices have been tried in attempts to prevent further oral trauma in patients who have bitten themselves. The devices for the patients whose conditions are considered long-term, i.e. the comatose and decerebrate are of a more permanent nature. One device uses intermaxillary fixation with arch wires in conjunction with hard oral acrylic devices. Some of the problems which can occur when the maxilla and mandible are wired together in this fashion include the inability of the patient to breath through his oral cavity, the inability of the patient's caregiver to maintain a patient airway by suctioning mucus and oral secretions from the patient's pharynx and the inability of the caregiver to deliver adequate oral hygiene measures to the patient. Tongue blades padded with gauze and wrapped with tape, hard and soft rubber and plastic mouth props, and flexible and inflexible metal and plastic airways have been used. Some problems which occur with these devices include an inability to keep them in their intended positions, between the patient's upper and lower teeth, unless a caregiver is managing the placement and positioning of the device at all times. If the patient opens wider than the device, as when yawning, the device may move into his throat or airway. If the patient thrusts his tongue forward against the device, he can push it out of his mouth. If the patient grinds his mandible from side to side he can also work the device out of his mouth or into his throat or airway. Customized soft and hard acrylic biteguards which cover the occlusal, facial and lingual surfaces of the upper and lower teeth have been used. In order to customize the acrylic biteguards to fit the patient's teeth and oral structures, impressions or imprints of the patient's dental arches must be obtained. The dental impression procedure can present risks to the patient's airway should the soft putty-like material be aspirated by the patient. The customized soft and hard acrylic biteguards can be dislodged from the teeth with tongue movements and grinding movements and create foreign body risks to the patient's airway and throat.
The protection used in the patients whose sensations to pain and pressure have been temporarily altered as a result of local mandibular dental anesthesia is frequently in the form of gauze padding or cotton rolls placed between the teeth on the non-anesthetized side of the mouth. By propping the teeth opened, oral tissues are not easily bitten. This protective procedure does not work well with patients who are unable to understand the logic of the instructions nor with those who are unable to comply with the instructions, i.e. children and the mentally handicapped. Therefore, the gauze padding and cotton rolls are frequently displaced, expelled and occasionally aspirated or swallowed.
Many different mouthguards have been designed to prevent mouth injury to patients. Some of these guards also have features particularly useful in keeping the throat of a patient under general anesthesia from becoming obstructed. Many of the prior mouthguards have complicated structures to accomplish these purposes.
The early patent of Freedland (U.S. Pat. No. 2,459,273) is for a shock therapy mouthguard with a rubbery pad mounted between the ends of a rigid handle. A longitudinal passage is formed on top of the handle on the pad. The lower teeth of a patient are placed between two arcuate projections on the lower surface of the pad. The disclosure of this patent and all other patents and publications cited herein is hereby incorporated herein by reference.
Other devices are simpler in form, being essentially a single U-shape (U.S. Pat. No. 4,867,147 of Davis) or Y-shape (U.S. Pat. No. 2,694,397 of Herms for a mouth prop with a flat handle having a recessed area between the handle and the arms positioned so that the upper front teeth do not touch the handle when the molars are positioned on the arms of the prop and having optional pads added to the top surface of the arms).
Even simpler is the disposable BITE.TM. jawlock of U.S. Pat. No. 3,971,370 which is simply a tongue depressing stick with a polyethylene pad at one end. For use in soft tissue oral protection and jaw positioning, a BITE.TM. jawlock is placed on one or both sides of the oral cavity. Because the BITE.TM. jawlock does not fill the oral cavity, it is often difficult to keep the two jawlocks in the correct place to prevent patient injury.
The patent of Ross (U.S. Pat. No. 2,833,278) is for a mouthguard comprising an upright "H" form in multiple planes. The teeth of the patient rest on the one portion and do not rest on the portions that extend above and below the top and bottom of the portion on which the teeth rest.
Many teeth protectors have a horizontal surface for the teeth to bite upon and a vertical surface extending upward from the front of the horizontal surface. See, for example, Brown (U.S. Pat. No. 1,302,004).
Some of the tooth guards have elaborate molded flanges for protection of the front teeth and an attached breathing tube (See U.S. Pat. Nos. 2,669,988 of Carpenter; 2,521,084 of Oberto; 2,882,893 of Godfroy; and 4,112,936 of Blachly).
Another standard type of teeth protector has a channel which surrounds the teeth, and in some cases also assists in treating the teeth. See, for example, Newman (U.S. Pat. No. 4,944,947: a device with recessed areas between surrounding side areas in which to place the teeth; Grossberg (U.S. Pat. No. 3,124,129); Martin (U.S. Pat. No. 3,385,291: the device has an upper and lower channel which partially surrounds the teeth with a rubber like material in the channels molded to conform with the gums and sides of the teeth); Hoef (U.S. Pat. No. 3,416,527: a U-shaped channel fabricated from a substance which will retain a liquid, with a liquid impermeable backing); Riddell (U.S. Pat. No. 3,060,935); and Castaldi (U.S. Pat. No. 5,031,638).
Other mouthguards are particularly designed for use by athletes, and are primarily made to surround and protect all of the player's teeth, for example, U.S. Pat. Nos. 3,496,939 of Gores and 5,082,007 of Adell. Other mouthguards are designed for use by persons undergoing operations requiring intubation, for example, U.S. Pat. No. 3,513,838 of Foderick, or to firmly depress and hold a patient's tongue, for example, U.S. Pat. No. 4,041,937 of Diaz.
Some of the devices are also designed to keep the tongue, lips and cheeks away from the teeth. See for example, Lee (U.S. Pat. No. 2,614,560) and Davis (U.S. Pat. No. 4,867,147).
It is important that mouthguards used for patients be both inexpensive to construct so that they can be disposable; be able to fit all patients, i.e, with different sizes of oral cavities or different numbers and arrangements of remaining teeth using a minimum number of mouthguard models; provide sufficient cushioning to minimize tooth damage; be resilient so as to withstand compression or perforation under biting forces; be flexible so as to allow contouring or bending of the planar single unit to adapt to the intra-oral and extra-oral surfaces; be nontoxic and non irritating to the oral mucosa or skin of the patient; and allow the anesthetized patient to be ventilated or the conscious patient to breathe through his mouth while the mouthguard is positioned in the oral cavity. It is also important that the device prevents the impingement and laceration of oral soft tissues, i.e., tongue, cheeks, and lips.
The mouthguard used should be able to be securely positioned in the oral cavity so as to neither be dislodged posteriorly which could compromise the patient's airway or throat or dislodged anteriorly which could expel the mouthguard from the patient's oral cavity. Additionally, the mouthguard should allow normal oral movements much as speaking, yawning and lateral movements of the mandible. The prior mouthguards generally are deficient in one or more of these aspects.
Minneman's mouthguard (U.S. Pat. No. 5,235,991) has a thin, stiff, generally triangular planar portion capable of deflecting mouth and cheek tissues, with arms along one side of the triangular plane and a single handle at an opposite end of the planar portion from the arms; and a compressible portion located on each arm and extending above and below the planar portion. This mouthguard is designed to prevent tooth and soft tissue injury in patients who are receiving ECT, but does not address the problem of self-inflicted trauma in the conscious patient or mechanical retention of the positioned mouthguard in the oral cavity of the conscious or unconscious patient so that constant supervision and management of the device by a caregiver is not necessary.
It is therefore an object of this invention to provide a mouthguard which can be manufactured inexpensively.
It is a further object of this mouthguard to have a minimum number of intra-oral shapes and sizes in order to be able to fit all patients, i.e., with different sizes of oral cavities or different numbers and arrangements of remaining teeth.
It is a further objective of this invention to provide a mouthguard which is effective in minimizing tooth damage and oral soft tissue damage to tongues, cheeks and lips.
It is a further object of this invention to provide a mouthguard which allows a patient to breathe through his mouth or to be ventilated while the mouthguard is in the patient's oral cavity.
It is a further object of this invention to provide a mouthguard which is resilient and able to withstand compression and perforation under biting forces and be flexible so as to be bendable and adaptable in order to contour to the intra-oral and extra-oral surfaces.
It is a further object of this invention to provide a mouthguard which is non-toxic to intra-oral tissues as well as non-irritating to extra-oral tissues.
It is a further object of this invention to provide a mouthguard which will not obstruct resuscitation or mouth-breathing.
It is a further object of the invention to provide a mouthguard which can be mechanically secured into its position in the oral cavity by a headstrap so as not to be displaced more posteriorly in the oral cavity or expelled out of the mouth.
Other objects and advantages will be more fully apparent from the following disclosure and appended claims.